From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
The working of a headlamp controller, comparing different dimming methods.
| Identifier | WestWitteringFiles\F\April1921\ Scan101 | |
| Date | 22th April 1921 | |
| Contd. -2- EFC3/T22.4.21. For further report on the working of the controller see attached sheet. It will be seen from this that the controller would apparently be better if the contained resistance was rather less, as it is not necessary or desirable that the two head lamps in parallel should be dimmed down beyond a certain minimum, which probably is similar to that obtained if the two lamps were put in series on the full voltage. Of the two devices, the series parallel switch is perhaps the simpler, but we think that the "Rex" head lamp controller would be much the more desirable type of the two, as everyone must agree that it would be definitely an advantage to be able to lower one's headlights gradually instead of suddenly, owing to the fact that in the last instance it is sometimes difficult to see the road. EFC. | ||